This invention relates to an injection drug dispensing system used e.g. in a hospital to dispense injection drugs in ampules or vials per prescriptions.
Drug preparation assisting systems are now used in many hospitals and pharmacies to help pharmacists to prepare drugs with higher efficiency and accuracy. The injection drug dispensing system shown in FIG. 15 is one of such assisting systems.
As shown, this dispenser system has a main conveyor 1, a bucket stocker 2 provided at the upstream end of the main conveyor 1, and a bucket discharging lifter 3 provided at the downstream end. Along the main conveyor 1 between the stocker 2 and the lifter 3, the dispensing system further includes dispensers 4 and 5 for dispensing injection drugs (hereinafter simply referred to as drugs) and a printer 6 for printing injection prescriptions.
The bucket stocker 2 supplies buckets 7 one by one onto the main conveyor 1. The main conveyor 1 is a conveyor (such as a roller conveyor) for feeding buckets 7 through the dispensers 4, 5 and the printer 6 to the bucket discharging lifter 3.
The dispenser 4 is of a type that requires drug items to be put in order, while the dispenser 5 asks no such orderly arrangement of drug items. Either dispenser has a plurality of cassettes 8 for storing different kinds of drugs separately from one another, and dispenses designated kinds of drug items by a designated number from a corresponding cassette 8.
As shown in FIG. 16, the dispenser 4 may include four drawer type storage units 9 each having a plurality of cassettes 8 arranged in a row.
At its bottom, each cassette 8 of each storage unit 9 has a discharge port 10. Near the port 10, a discharge roller 11 having a groove-shaped cutout is provided. A longitudinal belt conveyor 12 is provided under the cassettes 8 of each storage unit 9. Every time the discharge roller 11 in each cassette 8 rotates once, one drug item in the cassette 8 is discharged onto the belt conveyor 12.
An intermediate container 13 is provided at the downstream end of each longitudinal conveyor 12 to collect drug items a discharged. Each intermediate container 13 has an openable bottom cover 14. While not shown, a transverse conveyor extends under the intermediate containers 13 of the storage units 9.
The transverse conveyor has its delivery end disposed over the main conveyor 1. Drug items a collected in each container 13 are dropped onto the transverse conveyor by opening the cover 14, fed to the delivery end of the transverse conveyor, and dropped into a bucket 7 being fed on the main conveyor 1.
Either one or both of the dispensers 4, 5 may be used in the system. Also, if there are a large quantity of drug items to prepare, a plurality of such dispensers 4 and/or 5 may be installed along a longer main conveyor 1.
The printer 6 prints prescription data on drug items discharged from the dispensers 4, 5 and puts printouts into the corresponding buckets 7.
The bucket discharging lifter 3 has a bucket storage rack 16. Buckets 7 on the main conveyor 1 are picked up and put in the rack 16 by the lifter 17.
The units 1-6 of this conventional dispensing system are controlled by a computer 19 connected to the system through a control unit 18.
The computer 19 is connected to e.g. a host computer in a hospital. Every time dispensing data are received from the host computer, one bucket 7 is deposited on the conveyor 1 from the bucket stocker 2.
The computer 19 then activates the dispensers 4,5 to put prescribed drug items into the bucket 7 on the conveyor 1 and controls the printer 6 to print prescription information and put the printout into the bucket. At the delivery end of the conveyor 1, the bucket 7 is picked up and loaded into the rack 16 by the lifter 3.
An operator inspects each of the buckets 7 in the rack 16 for any missing or damaged drug items by consulting the prescriptions in the buckets.
On ordinary weekdays, hospital pharmacists prepare drugs to be administered to inpatients for the next day. But on Fridays or any other workday before a holiday, they have to prepare drugs for the next two, three or more days. On such days, they curse the conventional slow-speed dispensers.
Reasons why the conventional dispensing systems are slow in operating speeds are listed below:
(1) Slow dispensing speed
Of the two types of dispensers 4, 5, the dispenser 4, which requires drug items to be put in order, is especially slow in operating speed because dispensing data have to be written every time a drug item is discharged into an intermediate container. If drugs for a particular patient have to be supplied from a plurality of storage units, drugs in one intermediate container have to be discharged after drugs in another intermediate container have been discharged. This further prolongs the processing time.
(2) Finding any missing item is a time-consuming task.
At the inspection station, an operator has to count the number of drugs in each bucket and calculate in his head the number of any missing drug items, if any, by subtracting the actual number of drugs in each bucket from the number of drugs printed on the prescription.
(3) Once the system is stopped, a long time is needed before restart.
If an operator finds out that any item is missing, he has to stop the entire system. Once the system is stopped, the operator has to remove all the drugs and prescriptions remaining in the dispensers, printer and conveyors by opening the system case before restart. This of course prolongs the operating time. Further, the restart procedure itself takes a rather long time.
(4) Drugs tend to get jammed and broken.
Especially in a dispenser of a type in which drugs have to be arranged in order, drugs tend to get jammed and broken (such as on belt conveyors and in intermediate containers). Thus, the system has to be frequently stopped to remove such jammed or broken drug items. Drugs thus cannot be dispensed quickly enough.
An object of this invention is to provide an injection drug dispensing system which can increase the drug dispensing speed of a dispenser of a type in which drugs have to be stored in order therein, and which can prevent drug exhaustion error, reduce jamming and breakage of drugs, and which can quickly correct system failure.